worn out valve springs?

[FinGN]

What are the symptoms of worn out valve springs? My GN has about 102 K miles on it and I don't think the valve springs have ever been replaced. The car revs up to red line but seems to loose all its power after about 4000 rpm. Is it a difficult thing to change these springs? Mods so far: hot wired walbro 340, Adjustable fpr (45 psi) modified exhaust with double mufflers. Also got a Thrasher 92, but haven't tested it yet. I want to have everything else working as they should before changing chips etc. What's the usual mileage when one should change the valve springs?

 

[Kevin Turch]

Loss of top end power. I had mine done, but if i had to do it over i would probably try to do it myself. I think all you need is a removal tool, which i think u can make, and some compressed air.
HTH
Kevin

 

[6=8]

Hardest part about replacing the springs is compressing them so that they remain centered around the valve stem in order to replace the the keepers!

The job is not too tough. I recently did mine, and I am very happy that I did!

Kirbans has the springs and tool (Modified rocker arm and shaft) to do the job for $68. You will need an old rocker shaft, and an air compressor with a spark plug fitting to presurize the cyl to keep the valve in place. Also recommended are a new set of plugs, valve cover gaskets, intake valve seals, and a magnetic tool to fish the keepers in and out while you hold the spring compressor.

2-4 hours of your time... Maybe more if you need to fight the valve covers on or off on the pasenger side... It's a little tight over there!

If you don't have a compressor, you may be able to justify buying one using the labor charge/money you will save by doing it yourself!

 

[FinGN]

Thanks guys, I think I know now what's wrong. First I thought it's my tranny not upshifting in time, just over reving, but it's probably the loose springs that causes the feeling of over reving. I just have the stock tach for now, so no idea to know what the correct rpm's are. Have to get a real tach. I saw the Kirban spring kit with the tool and I'll probably go with that.